nfs: add export operations
This support for opening files on NFS by file handle, both through the
open_by_handle syscall, and for re-exporting NFS (for example using a
different version). The support is very basic for now, as each open by
handle will have to do an NFSv4 open operation on the wire. In the
future this will hopefully be mitigated by an open file cache, as well
as various optimizations in NFS for this specific case.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
[hch: incorporated various changes, resplit the patches, new changelog]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index c5054ed..2ebd574 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -10,6 +10,8 @@
#define NFS_MS_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS)
+extern const struct export_operations nfs_export_ops;
+
struct nfs_string;
/* Maximum number of readahead requests
